This is off topic if the topic is climbing. But somewhere in this sprawling STForum is a reference to the fact that today at 4:04 pm, the celestial conditions should have been such that it would be possible to recreate the Ansel Adams image "Half Dome and Moon" created in the winter of 1960 the result of Adams seeing the moon at 3:30pm as he drove to the Ahwahnee Hotel. This was on December 28, 1960 at 4:14pm.

I am particularly fond of shooting scenes that master photographers and painters have created images from, and Adams is famous for his love of having the moon appear in his images. Debbie volunteered to do the driving in case my back was a problem, which it was on the way home...

A professor of astronomy at Texas State has been having his students calculate the dates and times of famous Ansel Adams images, knowing the rough location and date time.... and so calculated this particular moon as having all the attributes of that moon position, the sun, etc...

but I was mostly worried that it would be a zoo out in the Ahwahnee Meadow, it turned out to be not too bad....

I was busy working out a good location to shoot it with my 180 mm lens on 35 mm film. Adams used a 250 mm lens on 120 format (2.25"x2.25")... Turns out that Google Earth is fun to play with this way...

Here is my calculation of the moon position from where I think Adams took his picture... the light box is the image on his film.

Credit: Ed Hartouni

You can see he cropped on the left hand side to have Washington Column, in the shadow of Glacier Point, boarder the image. Also he lined the moon up on the diagonal with the rounded corner of Half Dome, and the diagonal of the light and shadows in the image. It's impressive how quickly he worked, apparently there are 12 images on his contact sheet, he was using a Hasselblad so not quite as involved as using a view camera... still.

I worked out an other location to the south of Adams' point, and thought through where the moon would be. Since I had a tighter shot (I would have had to have a 166 mm lens to match the Adams image) I thought I'd get the moon along the boundary of rock and sky.

Credit: Ed Hartouni

culminating in the Adams image location, though with the moon a bit closer to Half Dome. (notice I can't count, the upper two moon markers should be "1600" and "1615", but I confused them... with 4:00 and 4:15).

Well we hiked a bit to shoot in a number of locations that I thought might be interesting, essentially on line with the Half Dome summit and Adams' point... for future reference.

I was shooting with my Nikon FM2N using Acros 100 B&W film (developed next week sometime) and with my FujiFilm S5 Pro digital camera. But it actually didn't matter...

...by 3:30pm there was a crowd growing, and it grew to about 50 - 60 people, mostly photographers, but a large NPS presence too... I counted 3 to 4 view cameras (probably 4" x 5")...

Credit: Ed Hartouni

My calculation should have had the moon rise in the notch at 3:30pm, but there were clouds trailing down Tenya Canyon from the high country, and there was nothing... and nothing at 3:45pm nor at 4:00pm... A lady walking by asked the photog next to us "Where's the moon?" to which he replied the same quip that I had to him just before "It's right there, we just can't see it." She didn't like that "If you've been divorced 3 times that's the reason why!" Debbie was chuckling about that at dinner, "she mustn't know any physicists."

Well I hung around a bit shooting the last of the roll playing with filters and exposures... the sun was down and it was starting to get cold. Then Debbie says, "THERE IT IS, THERE'S THE MOON" and so it was, just where it was supposed to be, at 4:44pm high above Half Dome.

Credit: Ed Hartouni

what a nice outing...
and how wonderful that serendipity plays so large a role in creating these wonderful images. Today was perfect, except the moon didn't want to come out and play with us.

very cool ed. my world just expanded. perfect example of "it's interesting to learn what climbers are interested in."

amazing tools available to us these days. for an astronomy class 40 years ago i pulled my hair out trying to figure out what the big dipper looked like from polaris. turns out the seven stars are in two groups nowhere near each other. but i learned respect for the guys that find this stuff easy. and now they're making it easy for the rest of us.

hope your back heals up soon, it's probably all you want for christmas, eh?

I made a couple outings to North Dome a few years ago, using an astronomy program and compass I was able to get some good shots and a time lapse film of the moon rising beside half dome.
Moon rise from North Dome is pretty amazing.

the idea of getting a close shot of Half Dome and the Moon is to have a time when the Moon is about the same altitude as the top of Half Dome when viewed from you vantage point...

The Ahwahnee Meadow is an altitude of 1200 m, it is roughly 4000 meters from the summit of Half Dome with an altitude of 2700 meters... the angle of the elevation is then:

angle = (2700 - 1200)/4000 = 0.375 radians = 21.5º

that sets the time after moon rise... if you're shooting from Ahwahnee Meadow.

What you should remember is that the Moon's path is essentially unchanged as viewed from your location in the Valley (or anywhere else) so that you move your location to place Half Dome where you want it in your shot with respect to the Moon. See that great shot by Lokesh above!

You'd like to know where the moon is, altitude and azimuth, locally, you can go on line and use a calculator putting in your coordinates (which make very fine tunes on the general location of Yosemite Valley roughly 37.75 N, -119.80 E)

I used this site: http://www.jgiesen.de/elevazmoon/index.htm to get the calculated elevation and azimuth of the moon, but it uses a Java Applet that Safari doesn't understand (hey you Apple dudes out there, what's up with that? it's really annoying that Apple doesn't at least try to recognize other Java dialects...) So use Firefox or some other browser if you're Mac bound.

The "azimuth" is just the local bearing, from the Ahwahnee Meadow Half Dome is roughly 90º (due East) so sometime between 4pm and 5pm tonight the Moon will be at the right height, but farther South than the Adams shot... which probably means behind Half Dome from that vantage point...

Here's what I'd do tonight: find a slightly higher point NORTH of the Ahwahnee by about 200 meters... there are practical problems like obscuration by Washington Column... Another vantage point might be to go to descent trail off of the Five Open Books, you're up at 1300 m elevation which will make Half Dome look lower with respect to the Moon, but if you go up there around 3:00 pm you'll get a good look at what is happening, and then position your image.

Here is my 180 mm on the digital (equivalent to a 270 mm in 35 mm format) from that trail

Here is the scene with an equivalent of a 93 mm lens in 35 mm format

Notice the mist swirling down from the high country which was the Moon's vail yesterday evening.

I didn't go any further North from the line through Ahwahnee Meadow and Half Dome summit (the location I was at in those last two shots was 11 m south of that line), but you'd hike a bit further along that trail to get the more than 200 meters (you are farther west (back) so you have to go farther North). I couldn't do that with Debbie because she is not a confident rock scrambler, and unless there are flowers involved (not this time of year!) there is no motivation for her to push beyond her unease. From this vantage point Washington Column is not an issue, but the image composition will be challenging absent a left boarder reference.

Thanks Ed.. I'm trying to decide if the convergence is still possible tonight, meaning the moon combined with the dome that will still have alpenglow on it... Thank God for the web cams, they saved me from driving up for nothing.. I could just tell it was gonna be cloudy around the dome at the critical time last night....

Yeah Ed, I agree with you. I think Columbia point or a little higher on the Falls Trail would be the spot.. I was wanting to shoot super telephoto like my posted pic, and not wider angle.. I'll probably just be lazy and stay home...

Ed,
Not OT, there's rock involved! Great stuff!
Lokesh - nice shot!
Walleye - Great shot! Part of me wants to see it slightly wider but it is tough to argue with tight (unless you prefer the wyde-lol).

I discovered a cable channel I didn't know I had. It is called Ovation and they are running a massive BBC-produced series this weekend called Framed - really great historical stuff. They had a bit on Ansel's other famous HD shot and the printing iterations it went through. A fairly recently discovered early print had the right side (I can't spell Tissa-whatever) of the wall all 'burned in' or dark. It looked much too contrasty to me plus I guess I like detail.

An excellent topic and great post. I don't know whether Ansel Adams wrote much about the how of his photography but the above reminds me of how Galen Rowell wrote about the thinking and estimating he did well in advance of the shots.